Could an arachnid-like animal realistically exist and survive at larger sizes? The specific dimensions are 2m tall, around 1m wide in the torso, and 3m long

An arachnid-like animal, for the purposes of this question:

  • They are divided into 2 parts, the prosoma and opisthosoma
  • The prosoma has all 10 limbs, which are mostly lizard-like in their overall shape
  • The front two limbs are the arms, which can grasp onto their prey and are attached to an insect-like pincer under the mouth, which is used similarly to jaws. The rest of the limbs are legs. The multiple uses of the forelimbs would require more reinforcement against more motions, and this problem will scale with size
  • They have many simple eyes distributed across the prosoma. These are the only visible sense organs, though their other hidden sense organs are still quite good at sensing. The wide spread of the eyes will necessitate long optic nerves, which are rarely seen on large creatures. The hidden sense organs will also be impacted by the growth, as the square-cube law prevents them from using their skin for smell as in arachnids, and vibrations will be harder to detect at the larger scales
  • They cannot consume solids, but can liquefy their prey with stomach juice in order to eat them. This may present issues with scale, due to the fact that the dissolved prey might seem less viscous and therefore harder to control
  • They consume relatively large prey (around 1m long usually)
  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – L.Dutch
    Oct 25, 2021 at 18:17

1 Answer 1


I'm going to say yes, but only due to two things.

The prosoma has all 10 limbs, which are mostly lizard-like in their overall shape

The front two limbs are the arms, which can grasp and are attached to an insect-like pincer under the mouth. The rest of the limbs are legs

This tells me your creatures are two things, not arachnids, and artificial. They might not be artificial but since they have mixtures of features from two kingdoms tell me it's unlikely. Point is they're not arachnids, which means they don't have an exoskeleton, and even if they do they have an endoskeleton anyway due to their lizard-like limbs, their 10 limbs instead of 8 are also tellers of them not being arachnids.

Them not being arachnids, and more than likely artificial, makes it likely for them to have some proper lungs, coupled with a more than likely endoskeleton and more advanced circulation system I don't think they're going to have much of an issue being large.

  • $\begingroup$ What about the other features I listed? Would they pose obstacles to reaching the stated size? $\endgroup$ Oct 25, 2021 at 15:03
  • $\begingroup$ @IchthysKing The eyes shouldn't hinder them too much, and neither will the food liquification or the frontal two arms. Being divided into two main parts might become an issue as a spinal support problem if the weight becomes too great, but you get women with some worryingly thin waists who seem to go about life fine so I don't think you'll get a problem until they become truly large. $\endgroup$
    – Lemming
    Oct 25, 2021 at 15:07
  • 3
    $\begingroup$ Lemming, just so you're aware, it really is best practice to refrain from answering questions that are being actively discussed, where people are asking for clarification or that are in the close queue. These are all red flags indicating that the question is not as well written or explained as it could be; or in this case, is a duplicate of another question. If you yourself as respondent are unsure enough about what the querent means so that you have to start your answer with "this tells me your creatures...are not arachnids", you really shouldn't be giving an answer! $\endgroup$
    – elemtilas
    Oct 25, 2021 at 15:40

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